New upstream version 1.9
[debian/gzip] / lib / stat-w32.c
diff --git a/lib/stat-w32.c b/lib/stat-w32.c
new file mode 100644 (file)
index 0000000..5d76a46
--- /dev/null
@@ -0,0 +1,421 @@
+/* Core of implementation of fstat and stat for native Windows.
+   Copyright (C) 2017-2018 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible.  */
+
+#include <config.h>
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+
+/* Ensure that <windows.h> defines FILE_ID_INFO.  */
+#undef _WIN32_WINNT
+#define _WIN32_WINNT _WIN32_WINNT_WIN8
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <limits.h>
+#include <string.h>
+#include <unistd.h>
+#include <windows.h>
+
+/* Specification.  */
+#include "stat-w32.h"
+
+#include "pathmax.h"
+#include "verify.h"
+
+#if _GL_WINDOWS_STAT_INODES == 2
+/* GetFileInformationByHandleEx was introduced only in Windows Vista.  */
+typedef DWORD (WINAPI * GetFileInformationByHandleExFuncType) (HANDLE hFile,
+                                                               FILE_INFO_BY_HANDLE_CLASS fiClass,
+                                                               LPVOID lpBuffer,
+                                                               DWORD dwBufferSize);
+static GetFileInformationByHandleExFuncType GetFileInformationByHandleExFunc = NULL;
+#endif
+/* GetFinalPathNameByHandle was introduced only in Windows Vista.  */
+typedef DWORD (WINAPI * GetFinalPathNameByHandleFuncType) (HANDLE hFile,
+                                                           LPTSTR lpFilePath,
+                                                           DWORD lenFilePath,
+                                                           DWORD dwFlags);
+static GetFinalPathNameByHandleFuncType GetFinalPathNameByHandleFunc = NULL;
+static BOOL initialized = FALSE;
+
+static void
+initialize (void)
+{
+  HMODULE kernel32 = LoadLibrary ("kernel32.dll");
+  if (kernel32 != NULL)
+    {
+#if _GL_WINDOWS_STAT_INODES == 2
+      GetFileInformationByHandleExFunc =
+        (GetFileInformationByHandleExFuncType) GetProcAddress (kernel32, "GetFileInformationByHandleEx");
+#endif
+      GetFinalPathNameByHandleFunc =
+        (GetFinalPathNameByHandleFuncType) GetProcAddress (kernel32, "GetFinalPathNameByHandleA");
+    }
+  initialized = TRUE;
+}
+
+/* Converts a FILETIME to GMT time since 1970-01-01 00:00:00.  */
+#if _GL_WINDOWS_STAT_TIMESPEC
+struct timespec
+_gl_convert_FILETIME_to_timespec (const FILETIME *ft)
+{
+  struct timespec result;
+  /* FILETIME: <https://msdn.microsoft.com/en-us/library/ms724284.aspx> */
+  unsigned long long since_1601 =
+    ((unsigned long long) ft->dwHighDateTime << 32)
+    | (unsigned long long) ft->dwLowDateTime;
+  if (since_1601 == 0)
+    {
+      result.tv_sec = 0;
+      result.tv_nsec = 0;
+    }
+  else
+    {
+      /* Between 1601-01-01 and 1970-01-01 there were 280 normal years and 89
+         leap years, in total 134774 days.  */
+      unsigned long long since_1970 =
+        since_1601 - (unsigned long long) 134774 * (unsigned long long) 86400 * (unsigned long long) 10000000;
+      result.tv_sec = since_1970 / (unsigned long long) 10000000;
+      result.tv_nsec = (unsigned long) (since_1970 % (unsigned long long) 10000000) * 100;
+    }
+  return result;
+}
+#else
+time_t
+_gl_convert_FILETIME_to_POSIX (const FILETIME *ft)
+{
+  /* FILETIME: <https://msdn.microsoft.com/en-us/library/ms724284.aspx> */
+  unsigned long long since_1601 =
+    ((unsigned long long) ft->dwHighDateTime << 32)
+    | (unsigned long long) ft->dwLowDateTime;
+  if (since_1601 == 0)
+    return 0;
+  else
+    {
+      /* Between 1601-01-01 and 1970-01-01 there were 280 normal years and 89
+         leap years, in total 134774 days.  */
+      unsigned long long since_1970 =
+        since_1601 - (unsigned long long) 134774 * (unsigned long long) 86400 * (unsigned long long) 10000000;
+      return since_1970 / (unsigned long long) 10000000;
+    }
+}
+#endif
+
+/* Fill *BUF with information about the file designated by H.
+   PATH is the file name, if known, otherwise NULL.
+   Return 0 if successful, or -1 with errno set upon failure.  */
+int
+_gl_fstat_by_handle (HANDLE h, const char *path, struct stat *buf)
+{
+  /* GetFileType
+     <https://msdn.microsoft.com/en-us/library/aa364960.aspx> */
+  DWORD type = GetFileType (h);
+  if (type == FILE_TYPE_DISK)
+    {
+      if (!initialized)
+        initialize ();
+
+      /* st_mode can be determined through
+         GetFileAttributesEx
+         <https://msdn.microsoft.com/en-us/library/aa364946.aspx>
+         <https://msdn.microsoft.com/en-us/library/aa365739.aspx>
+         or through
+         GetFileInformationByHandle
+         <https://msdn.microsoft.com/en-us/library/aa364952.aspx>
+         <https://msdn.microsoft.com/en-us/library/aa363788.aspx>
+         or through
+         GetFileInformationByHandleEx with argument FileBasicInfo
+         <https://msdn.microsoft.com/en-us/library/aa364953.aspx>
+         <https://msdn.microsoft.com/en-us/library/aa364217.aspx>
+         The latter requires -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
+      BY_HANDLE_FILE_INFORMATION info;
+      if (! GetFileInformationByHandle (h, &info))
+        goto failed;
+
+      /* Test for error conditions before starting to fill *buf.  */
+      if (sizeof (buf->st_size) <= 4 && info.nFileSizeHigh > 0)
+        {
+          errno = EOVERFLOW;
+          return -1;
+        }
+
+#if _GL_WINDOWS_STAT_INODES
+      /* st_ino can be determined through
+         GetFileInformationByHandle
+         <https://msdn.microsoft.com/en-us/library/aa364952.aspx>
+         <https://msdn.microsoft.com/en-us/library/aa363788.aspx>
+         as 64 bits, or through
+         GetFileInformationByHandleEx with argument FileIdInfo
+         <https://msdn.microsoft.com/en-us/library/aa364953.aspx>
+         <https://msdn.microsoft.com/en-us/library/hh802691.aspx>
+         as 128 bits.
+         The latter requires -D_WIN32_WINNT=_WIN32_WINNT_WIN8 or higher.  */
+      /* Experiments show that GetFileInformationByHandleEx does not provide
+         much more information than GetFileInformationByHandle:
+           * The dwVolumeSerialNumber from GetFileInformationByHandle is equal
+             to the low 32 bits of the 64-bit VolumeSerialNumber from
+             GetFileInformationByHandleEx, and is apparently sufficient for
+             identifying the device.
+           * The nFileIndex from GetFileInformationByHandle is equal to the low
+             64 bits of the 128-bit FileId from GetFileInformationByHandleEx,
+             and the high 64 bits of this 128-bit FileId are zero.
+           * On a FAT file system, GetFileInformationByHandleEx fails with error
+             ERROR_INVALID_PARAMETER, whereas GetFileInformationByHandle
+             succeeds.
+           * On a CIFS/SMB file system, GetFileInformationByHandleEx fails with
+             error ERROR_INVALID_LEVEL, whereas GetFileInformationByHandle
+             succeeds.  */
+# if _GL_WINDOWS_STAT_INODES == 2
+      if (GetFileInformationByHandleExFunc != NULL)
+        {
+          FILE_ID_INFO id;
+          if (GetFileInformationByHandleExFunc (h, FileIdInfo, &id, sizeof (id)))
+            {
+              buf->st_dev = id.VolumeSerialNumber;
+              verify (sizeof (ino_t) == sizeof (id.FileId));
+              memcpy (&buf->st_ino, &id.FileId, sizeof (ino_t));
+              goto ino_done;
+            }
+          else
+            {
+              switch (GetLastError ())
+                {
+                case ERROR_INVALID_PARAMETER: /* older Windows version, or FAT */
+                case ERROR_INVALID_LEVEL: /* CIFS/SMB file system */
+                  goto fallback;
+                default:
+                  goto failed;
+                }
+            }
+        }
+     fallback: ;
+      /* Fallback for older Windows versions.  */
+      buf->st_dev = info.dwVolumeSerialNumber;
+      buf->st_ino._gl_ino[0] = ((ULONGLONG) info.nFileIndexHigh << 32) | (ULONGLONG) info.nFileIndexLow;
+      buf->st_ino._gl_ino[1] = 0;
+     ino_done: ;
+# else /* _GL_WINDOWS_STAT_INODES == 1 */
+      buf->st_dev = info.dwVolumeSerialNumber;
+      buf->st_ino = ((ULONGLONG) info.nFileIndexHigh << 32) | (ULONGLONG) info.nFileIndexLow;
+# endif
+#else
+      /* st_ino is not wide enough for identifying a file on a device.
+         Without st_ino, st_dev is pointless.  */
+      buf->st_dev = 0;
+      buf->st_ino = 0;
+#endif
+
+      /* st_mode.  */
+      unsigned int mode =
+        /* XXX How to handle FILE_ATTRIBUTE_REPARSE_POINT ?  */
+        ((info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ? _S_IFDIR | S_IEXEC_UGO : _S_IFREG)
+        | S_IREAD_UGO
+        | ((info.dwFileAttributes & FILE_ATTRIBUTE_READONLY) ? 0 : S_IWRITE_UGO);
+      if (!(info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY))
+        {
+          /* Determine whether the file is executable by looking at the file
+             name suffix.
+             If the file name is already known, use it. Otherwise, for
+             non-empty files, it can be determined through
+             GetFinalPathNameByHandle
+             <https://msdn.microsoft.com/en-us/library/aa364962.aspx>
+             or through
+             GetFileInformationByHandleEx with argument FileNameInfo
+             <https://msdn.microsoft.com/en-us/library/aa364953.aspx>
+             <https://msdn.microsoft.com/en-us/library/aa364388.aspx>
+             Both require -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
+          if (info.nFileSizeHigh > 0 || info.nFileSizeLow > 0)
+            {
+              char fpath[PATH_MAX];
+              if (path != NULL
+                  || (GetFinalPathNameByHandleFunc != NULL
+                      && GetFinalPathNameByHandleFunc (h, fpath, sizeof (fpath), VOLUME_NAME_NONE)
+                         < sizeof (fpath)
+                      && (path = fpath, 1)))
+                {
+                  const char *last_dot = NULL;
+                  const char *p;
+                  for (p = path; *p != '\0'; p++)
+                    if (*p == '.')
+                      last_dot = p;
+                  if (last_dot != NULL)
+                    {
+                      const char *suffix = last_dot + 1;
+                      if (_stricmp (suffix, "exe") == 0
+                          || _stricmp (suffix, "bat") == 0
+                          || _stricmp (suffix, "cmd") == 0
+                          || _stricmp (suffix, "com") == 0)
+                        mode |= S_IEXEC_UGO;
+                    }
+                }
+              else
+                /* Cannot determine file name.  Pretend that it is executable.  */
+                mode |= S_IEXEC_UGO;
+            }
+        }
+      buf->st_mode = mode;
+
+      /* st_nlink can be determined through
+         GetFileInformationByHandle
+         <https://msdn.microsoft.com/en-us/library/aa364952.aspx>
+         <https://msdn.microsoft.com/en-us/library/aa363788.aspx>
+         or through
+         GetFileInformationByHandleEx with argument FileStandardInfo
+         <https://msdn.microsoft.com/en-us/library/aa364953.aspx>
+         <https://msdn.microsoft.com/en-us/library/aa364401.aspx>
+         The latter requires -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
+      buf->st_nlink = (info.nNumberOfLinks > SHRT_MAX ? SHRT_MAX : info.nNumberOfLinks);
+
+      /* There's no easy way to map the Windows SID concept to an integer.  */
+      buf->st_uid = 0;
+      buf->st_gid = 0;
+
+      /* st_rdev is irrelevant for normal files and directories.  */
+      buf->st_rdev = 0;
+
+      /* st_size can be determined through
+         GetFileSizeEx
+         <https://msdn.microsoft.com/en-us/library/aa364957.aspx>
+         or through
+         GetFileAttributesEx
+         <https://msdn.microsoft.com/en-us/library/aa364946.aspx>
+         <https://msdn.microsoft.com/en-us/library/aa365739.aspx>
+         or through
+         GetFileInformationByHandle
+         <https://msdn.microsoft.com/en-us/library/aa364952.aspx>
+         <https://msdn.microsoft.com/en-us/library/aa363788.aspx>
+         or through
+         GetFileInformationByHandleEx with argument FileStandardInfo
+         <https://msdn.microsoft.com/en-us/library/aa364953.aspx>
+         <https://msdn.microsoft.com/en-us/library/aa364401.aspx>
+         The latter requires -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
+      if (sizeof (buf->st_size) <= 4)
+        /* Range check already done above.  */
+        buf->st_size = info.nFileSizeLow;
+      else
+        buf->st_size = ((long long) info.nFileSizeHigh << 32) | (long long) info.nFileSizeLow;
+
+      /* st_atime, st_mtime, st_ctime can be determined through
+         GetFileTime
+         <https://msdn.microsoft.com/en-us/library/ms724320.aspx>
+         or through
+         GetFileAttributesEx
+         <https://msdn.microsoft.com/en-us/library/aa364946.aspx>
+         <https://msdn.microsoft.com/en-us/library/aa365739.aspx>
+         or through
+         GetFileInformationByHandle
+         <https://msdn.microsoft.com/en-us/library/aa364952.aspx>
+         <https://msdn.microsoft.com/en-us/library/aa363788.aspx>
+         or through
+         GetFileInformationByHandleEx with argument FileBasicInfo
+         <https://msdn.microsoft.com/en-us/library/aa364953.aspx>
+         <https://msdn.microsoft.com/en-us/library/aa364217.aspx>
+         The latter requires -D_WIN32_WINNT=_WIN32_WINNT_VISTA or higher.  */
+#if _GL_WINDOWS_STAT_TIMESPEC
+      buf->st_atim = _gl_convert_FILETIME_to_timespec (&info.ftLastAccessTime);
+      buf->st_mtim = _gl_convert_FILETIME_to_timespec (&info.ftLastWriteTime);
+      buf->st_ctim = _gl_convert_FILETIME_to_timespec (&info.ftCreationTime);
+#else
+      buf->st_atime = _gl_convert_FILETIME_to_POSIX (&info.ftLastAccessTime);
+      buf->st_mtime = _gl_convert_FILETIME_to_POSIX (&info.ftLastWriteTime);
+      buf->st_ctime = _gl_convert_FILETIME_to_POSIX (&info.ftCreationTime);
+#endif
+
+      return 0;
+    }
+  else if (type == FILE_TYPE_CHAR || type == FILE_TYPE_PIPE)
+    {
+      buf->st_dev = 0;
+#if _GL_WINDOWS_STAT_INODES == 2
+      buf->st_ino._gl_ino[0] = buf->st_ino._gl_ino[1] = 0;
+#else
+      buf->st_ino = 0;
+#endif
+      buf->st_mode = (type == FILE_TYPE_PIPE ? _S_IFIFO : _S_IFCHR);
+      buf->st_nlink = 1;
+      buf->st_uid = 0;
+      buf->st_gid = 0;
+      buf->st_rdev = 0;
+      if (type == FILE_TYPE_PIPE)
+        {
+          /* PeekNamedPipe
+             <https://msdn.microsoft.com/en-us/library/aa365779.aspx> */
+          DWORD bytes_available;
+          if (PeekNamedPipe (h, NULL, 0, NULL, &bytes_available, NULL))
+            buf->st_size = bytes_available;
+          else
+            buf->st_size = 0;
+        }
+      else
+        buf->st_size = 0;
+#if _GL_WINDOWS_STAT_TIMESPEC
+      buf->st_atim.tv_sec = 0; buf->st_atim.tv_nsec = 0;
+      buf->st_mtim.tv_sec = 0; buf->st_mtim.tv_nsec = 0;
+      buf->st_ctim.tv_sec = 0; buf->st_ctim.tv_nsec = 0;
+#else
+      buf->st_atime = 0;
+      buf->st_mtime = 0;
+      buf->st_ctime = 0;
+#endif
+      return 0;
+    }
+  else
+    {
+      errno = ENOENT;
+      return -1;
+    }
+
+ failed:
+  {
+    DWORD error = GetLastError ();
+    #if 0
+    fprintf (stderr, "_gl_fstat_by_handle error 0x%x\n", (unsigned int) error);
+    #endif
+    switch (error)
+      {
+      case ERROR_ACCESS_DENIED:
+      case ERROR_SHARING_VIOLATION:
+        errno = EACCES;
+        break;
+
+      case ERROR_OUTOFMEMORY:
+        errno = ENOMEM;
+        break;
+
+      case ERROR_WRITE_FAULT:
+      case ERROR_READ_FAULT:
+      case ERROR_GEN_FAILURE:
+        errno = EIO;
+        break;
+
+      default:
+        errno = EINVAL;
+        break;
+      }
+    return -1;
+  }
+}
+
+#else
+
+/* This declaration is solely to ensure that after preprocessing
+   this file is never empty.  */
+typedef int dummy;
+
+#endif